Method of excavating earth.



H. L. DOHERTY. METHOD OF EXCAVATINGEARTHK APPLICATION men MAYiS, 1911.

1,166,820. Patented Jan. 4,1916.

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COLUMBIA PLANOGRAPH co., WASHINGTON, D. c.

HENRY L. noHEB'rY, orivnw YORK, N. Y.

METHOD or nxoAvA'rINe EARTH.

Application filedMay 15, 1911. Serial N 0. 627,132. 1

To all whom it may concern: 7 V

Be it knownthat I, HENRY L. DOHERTY, a citizen of the United States, anda resident of New York city, in the county of New York and State of NewYork, have invented certain new and useful Improvements in Methods ofExcavating Earth, of which the following is a specification.

My invention relates to methods of .excavating earth.

The object of my invention is to improve present methods of excavatingby supplying to the art a method which will permit of the cutting looseof the material and the removal of the same from the excavation with aminimum expenditure of power.

Briefly stated, the important features of my invention are the cuttingfree of the material on an overhanging face whose angle with thehorizontal is less than or equal to the angle of repose of the excavatedmaterial, and receiving the excavated material upon and transferrlng itout of the excava tion upon a belt conveyer working substan tiallyparallel to the working face. The material is excavated from the workingface in successive layers, each layer being excavated by-cutting one ormore furrows uniformly spaced relative to the excavation and thensuccessively cutting other furrows right and left from the initialfurrows until the full width of the layer has been excavated.

In the accompanying drawings I have shown a form of apparatus capable ofapplying my invention. The drawings are somewhat diagrammatic incharacter.

Figure 1 shows a partial side elevation of theapparatus with the windingdrums and gear for winding the cables which suspend the boom of theexcavatingfframe,omitted. Fig. 2 is a top view of the same showing; thewinding drums mentioned also. Fig. 3 is a cross-section of apparatus onthe line AB of Fig. 1 showing the forward part of the machine in rearelevation. Fig. 4 is a partial side elevation of the excavating boom.Fig. 5 is a cross-section of the excavating boom on the line C-D. Fig. 6is a front view on an enlarged scale of an intermediate cutter mountedon its bar. Fig. 7 is a side elevation ofthe same. Fig. 8 is an enlargedfront view of one of the end cutters showing the discharge chute forthrowing.

the excavated material away from the'side of the cut on to the conveyerbelt. Fig 9 Specification of Letters Patent;

width of the Patented J an. 4, 1916.

a corresponding side elevation of the same. Fig. 10 is a side elevationof the flat linked chain or sprocket-chain which carries the cutterbars. Fig. 11 is a diagram of a portion of the working face of theexcavation showing a full set of cutters and the way. in

which the working "face is furrowedby the cutters. Fig. 12 is a plan ofthe frame of the excavator proper.

1 is the excavator proper. It has a rigid frame made up of the heavy endyokes 2 and V I 3 and longitudinal beams l and 5 attached thereto.Journaled in suitable -bearings in the projecting arms F-and 5 of theend yoke 3 is a shaft 6 which carries the polygonal drums 7 and 8 overwhich the sprocket v chains of the cutter frame work and the drum 9 overwhich works the conveyor belt 10. The upper end yoke 2 has theprojecting arms 11 and 12 which carry suitable hearings in which isjournaled the heavy shaft 13. 13 carries the sprocket wheels 14 and 15,which drive the chains16 and 17 bearing the cutters, and the drum 18which drives the conveyer belt 10. At suitable intervals in the sprocketchains 16 and 17 are interposed special links 19, having a yoke socket,which sockets receivethe ends of the cutter bars 20. These speciallinks-are, of course, spaced at corresponding intervals on the chains 4mounted so that the corresponding links on each chain come exactlyopposite each other. Bolts, 21, fasten the bars 20 in the yokes of links19 Mounted on the bars 20 are the cutters. These are of twotypes. IFirst are the plows 22 which make the initial cuts in the work ing face.These are simply miniature plows designed to throw a narrow furrow about16 and 17 and the chains are 7 2 inches wide and four inches deep. The

width and depth of the cut may, of course, be varied in any. given caseto suit the soil andthe conditions by substituting plows designed togive the particular cut desired. Following the plows 22 are thescoop-cutters 23. These each have three cutting edges, a, b and 0, sothat each cutter makes two vertical cuts and simultaneously a connectinghorizontal cut. These cutters 23 are, in reality,jeach combinations ofright and left cutters, and out two separate furrows on each side of thesmall furrows'made by the plows22." The upper cutting blade b isattached to a hood-like piece 24 having a d a curvature such thatwhilethe cut a which the cutters are mounted is. passing over thepolygonal wheels 7 and 8 at the lower end of the excavator they will notcontact with the face of the cut made-by their cutting edges. A sheet 25forms the back, and side sheets 26 the sides, of the scoop. The scoopsare attached to the stems 27 whose upper parts are bent to hold thescoops in the proper position relative to the working face of theexcavation.

Following the cutters 23 are sets of two single cutters 28 and 28. Theseare constructed to cut respectively to the right and left of the furrowsleft by 22 and 23, the right hand cutters being numbered 28 and the lefthand cutters 28. These each make one vertical cut (to the right and leftof the initial furrows respectively) and simultaneously one cross-cutjoining the vertical cut with the furrow of its cooperating plow 28.Otherwise their construction is sub stantially similar to that of thefirst set of cutters 23. Following 28, 28 are two intermediatescoop-cutters and end cutters 29 and 29. The cutters 30 are similar tothe cutters 23 in shape but have no vertical cutting blades and are madeslightly wider so as to overlap the ridges left by the precedingcutters. The end cutters 29 and 29 are similar to the single cutters 28,28 respectively with the addition of dirt chutes 99, 99 respectively.These chutes 99, 99, have both a transverse and backward curvature. Thebackward curvature should be such as to permit the freest movement ofthe dirt possible, so as to reduce the friction and possibility ofclogging the chutes to a minimum. With the shape shown, the forwardmovement of the chute materially facilitates the discharge of the dirtfrom the chute, onto the conveying belt 10.

Any form of excavator for accomplishing the process may be used. After acut with an overhanging face has been made a plurality of longitudinalfurrows are cut in the under side of the overhanging face to a certaindepth, for instance, by 'suchplows as are shown at 22. Then the underside of the face is furrowed on each side of each of the furrows made byplows 22. One furrow is made on each side of the furrow made by thefirst plow 22 and at the same time a substantially horizontal cut, or acut parallel with the working face, is made, connecting the two furrowsstraddling the furrow made by the first plow. The cutters 28advantageously make these two furrowsandeliminate the earth betweenthem, cutters 23 being provided with cutting edges to connect thevertical cuts to each side of the first furrow and with a cutting edgejoining the two 7 vertical cutting edges to make the substantiallyhorizontal cut. After the first furrow has been made and afterthe-second two furrows have been made and the earth between themeliminated, all of which results in the formation of a relatively narrowgroove, scoop cutters 28 widen the grooves by making a vertical cutsubstantially the same depth as the initial furrow and also making ahorizontal cut substantially parallel with the working face. This ofcourse widens the groove into what may be termed a channel. The cuttersall are spaced such a distance apart and are set in such a way that whenthe number here shown, for the sake of illustration, are used the lastset of cutters 30 and 2929"operate to complete the excavation of onelayer. Cutters 28 and 28 having widened the grooves and made a channelhave left a series of downwardly projecting ribs. These ribs are in thepath of the cutters 30 which need therefore only be provided with ahorizontal cutting edge. This advantageously projects upwardly to pareoff or slice the rib the same depth as the initial furrow, the secondfurrows made by cutters 23, and the height of the walls left by thecutters 28 and 28. Preferably along the same line as cutters 3O cutters29 and 29 operate to pare slicesof earth from opposing walls left in theoverhanging face by extreme cutters 28 and 28. Cutters 29 and 29 aresimilar to the cutters 28 and 28 except that they are provided with dirtchutes. These dirt chutes direct the dirt inwardly as the cutters 29 and29 make their vertical cuts and their'cuts parallel with the workingface. The earth falls by gravity as it is eliminated from theoverhangingface upon the conveyer which conducts it from out of the-cut.In other words, first a deep furrow is made, then two other furrowsofthe same depth are made alongside it and the earth thus loosened ispared off by a cutting edge working in a plane parallel to the plane ofthe working and at a depth equal to the depth of the first furrows. Thenthe opposite walls of the groove thus formed are sliced or pared bysucceeding cutters. The lateral support of the earth is eliminated sothat after the furrow is made the earth may easily be pared or sliced.It will be noted that after the first furrow is made the earth mayeasily be pared or sliced. It will also be noted that after the firstfurrow is made each cutter is operating practically to cuta verticalwall which has support only on one side.

As shown, the cutters of the several grou-psof cutters in each set orseries may be set at variable distances from the bars 20. The stems 27of the cutters are inserted in the heavy sockets 30 mounted on the bars20 and pass through openings in the latter when set low. Keys 31,inserted in suitable keyways in the sockets 30, hold the stems 27 in thedesired position. By setting the cutters in this way I am enabled, aswill be more fully explained hereinafter, to remove layers ofsubstantially uniform thickness while moving the whole apparatus forwardcontinuously.

The cutters described, taken together, constitute one cooperating set inechelon arrangement andmake one full cut across the full width of theexcavation. This latteris governed,of course, by the width of theexcavator frame and theisize and number of the cutters must be arrangedaccordingly, so that the combined furrows made by the individual cutterswill form a clearrcut across the working face. The size and arrangementof the cutters constituting a set having been decided upon, the frameand sprocket chains must be made of such length as to permit themounting of the cutters in full sets. In the arrangement shown, thereare four complete sets of cutters mounted on the excavator 1. As shown,the ends of the cutter bars 20 are supported upon rollers 32 which rollalong the track formed by the angle irons 33, which latter are in turnsupported by the I-beams 4 and 5. i

The excavated dirt falls upon the belt 10 and is carried on the beltover the upper driving drum l8 and discharged upon another conveyerwhichwill be described later. Rollers 3f, ournaled in bearings in thebrackets 35 attached to the I-beams 4c and 5, serve to support the belt.

It is apparent that the belt 10 would be unable to pick up the dirtexcavated near the bottom of the working face. It is to take care ofthis point that the scoop form is given to the cutters. With this formof cutter, while the cutter is traveling around the lower polygonalWheels 7 and 8, all the dirt excavated by the cutter falls into thescoop and is carried up and over the drums. The slant of the sheets 25forming the backs of thescoops relative to the frame of l is such that,when the scoops have again assumed a rectilinear motion, the contents ofthe scoops will discharge, under the influence of gravity, onto the belt10, which will carry it over the upper drum 18 as above described.

.The speed-of the cutters should be comparatively high relative to therate of forward movement of the machine as a whole. The speed of coursevaries, but in ordinary alluvial ground will usually be at least 5!; ft.per second and may be as high as 8'or' 9 ft.

per second. If the excavator 1' is working on an overhanging face havingan angle of 30 with the horizontal, 2 inches of cut on'the working facewill mean that the machine as a whole can move forward 4c lnches 1n theperiod, while practicable from a mechanical point of view, would be veryinefficient and. awkward in practice. Therefore I prefer to operate theapparatus with a uniform forward motion proportional to the speed atwhich it is excavating. To secure this conditi'on it is necessary to setthe cutters in each group of a set at diflerent distances from theirrespective cutting bars. The exact distance towhich they will be offsetdepends, in any given case, upon the speed of the cutters and theinterval between the adjacent groups. The setting should be such thatthe following cutters will be nearer the cutting bar than the leadingcutters by a distance approximately equal to the forward movement of themachine during the period required for the cutters to traverse adistance on the working face equal to the interval between'the' leadersand followers. Since the" amount of this forward movement dependsuponthe angle with the horizontal at which the excavator 1 is working,it is evident that the cutters should be reset for any materialvariation of this angle. The excavator l is supported from the heavyshaft 13-which, in turn, is supported in the bearings 36 and 36 carriedby the arms 37 and 37' of the boom frame 38. 38 is made up of ayoke-piece 39, having the arms 37 and 37 and the two supporting arms 40and 40. These arms 40 and 40 are supported by the shaft 63, which inturn is supported by bearings 41 and 41 carried by the standards 42 and42, respectively. These standards rest upon the heavy frame, 43, of themachine. Heavy guy rods, 4:4 and 44:, respectively, attached to the mainframe of the machine counteract theturning moment exerted by the boomand excavator, while cross-braces, 45, 46 and 4L7, give additionalstability to the standards. Suitable cables, L8 and 48., attached to theboom 38 support the latter in the desired position. The cables,

as shown, are carried over pulleys, 49 and 4.9,-respectively, borne bythe standards 42 and 42, respectively; 'From l9 and t9 the cables arecarried through appropriate guide. pulleys to the winding apparatus 50.This, as shown, comprises a winding drum, 51, rotatedthrough a suitabletrain of gears by the shaft 52'by shifting the clutch 53 into the properposition.

Rigidly attached 12 jof-the frame of the excavator are the] large gears54: and 54, respectively. Thesemesh with the small gears 55 and 55,respectively, carried on the shaft 56. Carried alsoon the shaft 56 arethe gears 57 and 57 which mesh with the gears 58 and 58 on the shaft 59.Mounted on the shaft 59 is the sprocket wheel 60 carrying the sprocketchain 61. The driving sprocket 62 is mounted loosely on the shaft 63. 62is arranged to be thrown in or out of gear by means of to'the yoke arms11 and V the lever 6a which actuates a clutch, 65. The 3p shaft 63 issupported in suitable bearings, 41 and 41', carried on brackets attachedto the standards 42 and 4:2. 63 also carries the pulley 66 and thedriving sprockets 67 and 6? which drive the main sprocket chains 68and68, respectively, which work, respectively, over the sprocket wheels69, 69 attached to the shaft 13. A belt, 70, directly connects thepulley 66 with the pulley 71 on the shaft 72 of engine 78. This lattermay be a gasolene engine, as shown, a steam engine or an electric motor,having connection with a trolley working on a trolley Wire supported bymovable poles mounted on trucks.

The excavated dirt, as before mentioned, is raised by the belt 10 of theexcavator, and discharged over the driving drum 18 onto the belt M ofthe conveying mechanism 7 5. Inclined sheets, 76 and 7 6, guide thefalling material onto the belt 74. A sheet, 77, prevents any materialrolling down the belt, on account of the energy imparted to it by thefall, and 05 the lower end of the same. The conveyer 7 5 is of coursearranged to work on a less angle than the angle of repose of thematerial being excavated. Any suitable type of belt conveyer may be usedfor mechanism 7 5. The excavated material discharges from the belt 74onto the conveyer 7 8. This, like 74, is an ordinary belt conveyer. Itis arranged so that it discharges the dirt either into wagons or simplydumps it upon the surface of the ground at a sufficient distance fromthe ditch to prevent it falling back,

The conveyer 75 is operated from the shaft through a suitable sprocketor other gear. As shown, the driving drum 79 of 7 5 carries a sprocket,80, and is driven from the sprocket 81 on shaft 82 through the chain.83. The shaft 82 also carries the sprocket which drives sprocket 85 onshaft 86 which in turn drives the drum 87 of elevator 78 through thebevel gear 88. Shaft 82 is driven from shaft 63 by means of the chainand sprocket gear 89. The other end of the conveyer 78 is supported andthe angle on which it works varied by the cables 90 which are carriedover suitable pulleys and wound on the hand windlass 91, driven througha suitable gear by the crank 92.

Locomotion of the machine as a whole is effected by means of a chain andsprocket gear attached to the rear axle of the machine and to the shaft52 is driven through a suitable train of gears from the shaft 93, whichlatter receives its motion from the crank shaft of engine 73 through thebelt 1 94. By means of the clutch 95 the chain and sprocket gear to therear axle may be thrown in or out of gear as desired.

My invention may be applied either to making large excavations or Simpletrenches. The method of operating the apparatus shown to carry out myinvention is as follows: To start the cut, the boom frame 38 is loweredto the proper distance by allowing the cables 48 and 3 .8 to unwind fromthe drum 51 until the boom 38 has assumed the position desired. Thelock, 97, of the rotating gear of the excavator 1 is now released andunder control of the brake, 96, the end of the excavator table 1 ispermitted to drop until the end is on the ground. The engine 73 being inoperation, and the belt 70 on the tight pulley 66, the mechanism drivingthe chains 16 and 17 which bear the cutters, and the conveyer belt 10are set in operation. The cutters mounted on the bars 20 which arecarried by the chains 16 and 17 slice or peel off layers of dirt fromthe overhanging surface, the dirt thus cut loose falling freely downwardupon the belt 10 of the excavator 1, which delivers it to conveyer 75,then onto conveyer 78, which latter dumps it, either into a wagon or onthe surface of the ground alongside the cut.

As the machine progresses, the boomframe 38 is gradually lowered so thatthe cut made by the excavator is made on an incline, the angle of theinclination-depending upon the rate at which the boom-frame is lowered.l/Vhen the front wheels of the truck enter the cut the boom-frame 38must be raised somewhat in order to keep the bottom of the cut on theproper angle. The raising of the boom-frame is performed by throwing inthe clutch 53 of the winding apparatus 50. This winds in the cables 58and thus raises the boom-frame. By throwing out-the clutch 53 andthrowing in the pawl (or other locking device) 98 the boom is maintainedin the proper position. When the inclined cut has reached the desireddepth the boom-frame is again raised so that the excavator will cut onthe horizontal. This new position is maintained until the front wheelsof the truck have entered upon the horizontal cut. From this positionthe boomframe must be again gradually dropped until the rear wheels havealso entered upon the horizontal, when the boomframe may be againadjusted in a fixed position.

During the manipulation of the boomframe, it is necessary to vary theangular position of the excavator relative to the boomframe so that theangle which the excavator makes with the horizontal will not exceed theangle of repose of the material being excavated. Otherwise the dirtdischarged onto the belt 10 would simply roll back again to the bottomof the trench. This rotation of the excavator is accomplished bythrowing in the clutch when the rotation of the shaft 63 causes arotation of the gears 54: and 54: rigidly fastened to the frame of theexcavator, and hence causes rotation of the latter also.

' inclination of the excavator.

' It is to be noted that in entering the ground the excavator goes in ona V or wedge-shaped cutthe plane angle formed by the hanging roof andthe bottom of the cut depending of course upon the angle of This is avery important feature of my invention. It enables me to reduce thepower required for the cutting out and removal of the excavated materialto a minimum. Instead of'being under the necessity of scraping the dirtout of the excavation in themanner'which is practised in the case of allof the mechanical excavators of which I have knowledge, and which isvery wasteful of power, I remove the excavated material from the trenchby carrying it on a belt conveyer-the cheapest known method of handlingfine materials.

An extremely important feature of the present invention is theparticular method of cutting the dirt from an overhanging surface asdescribed and ascarried out, for example, by means of the apparatus hereillustrated. With the exception of the initial cutters or plows 22, thecutters which loosen I the dirt simply make two knife-cuts at rightangles to each other, the other two sides of each prism of dirt beingalready free, the cutters acting merely as paring or peeling members andnot as scrapers. The dirt thus freed simply falls by gravity onto thebelt 10. There is thus no digging or scooping necessary on the roof faceof the cut. The

power required is only that necessary to draw a sharp bladed knifethrough the earth,

and it is evident that it is therefore the least possible, since the cutis made, in each case, only a short distance in from a free face of thedirt prism (four inches as shown) so that the knife, acting as a narrowwedge, easily displaces the dirt laterally. Having described myinvention, what 1 claim is:

1. The process of excavating earth which comprises first forming anoverhanging working face; then makmg a longitudinal cut in said face;then making a cut along lines each side and parallel to the first cutveying away the earth thus severed from said working face.

2. The process of excavating earth which comprises first forming I anoverhanging working face; then making a longitudinal cut in said face;then makinga out along. lines each side and parallel to the first cutand also a cut parallel to the working face tween said last two cutsparallel to the between the said lines whereby the first cut is widenedinto a groove; then further widening the groove by making a vertical outalong a line on each side of the groove in the working face and bymaking cuts each at an angle to said last line and extending to thefirst two lines; then paring the earth from the opposite walls of saidfurther ing a plurality of pairs of cuts each parallel.

to said first furrows and to substantially the same depth, the cuts ofeach pair straddling one of said first furrows; severing the earthsubstantially parallel to the working face between the cuts of each pairby cutting on a line extending inwardly from each of last said cutstoward the straddled furrow and substantially parallel with the workingface; then widening the so-made grooves by cutting away portions ofopposite walls, thus leaving on said overhanging working face aplurality of downwardly projecting longitudinal ribs; then eliminatingsuch ribs by cutting the earth at a depth substantially equal to thedepth of first saidfurrows and parallel to the working face; andcollecting earth thus severed and conveying it from under said faceoutside of said cut.

4. The process ofexcavating earth which comprises forming a cut with anoverhanging working face; then making a plurality of longitudinalfurrows to a predetermined.

depth in said face; then making a cut on each side of the said firstfurrow and simultaneously cutting away said earth between said last twocuts leaving parallel to the working face grooves having oppositewallsthen vertically making a. cut in the said face to one side of each ofsaid walls of each groove and simultaneously cutting the earth betweensaid last cuts and said walls leaving wider channels than said grooves,then cutting parallel to and from said face the remaining earth betweensaid channels and at the same time cutting and inwardly direct-f ing theearth from said face and the outer walls left by the elimination of theearth in said channels, and collecting and conveylng the earth from saidface outslde of the cut.

depth in said face; making a cut on each side of the said first furrowsto substantially the same depth as the first furrows and simultaneouslycutting away the earth be- Working face, thus leaving in said face aplurality of grooves having opposite walls; then vertically making cutsto substantially the same depth as said furrows in said face to one sideof each of the said walls of each groove and simultaneously cutting awaythe earth between the last two cuts parallel to the working face, thusleaving channels wider than said grooves; then cutting parallel to andfrom the said face the remaining earth between said wider channels andat the same time cutting from and inwardly directing the earth from saidface and the outer walls which are left by said channels; and collectingand conveying the earth thus severed from said face outside of the cut.

Signed at New York city, in the county of New York and State of New Yorkthis 13th day of May, A. D. 1911.

HENRY L. DOHERTY.

Witnesses:

FRANK L. BLACKBURN, S. B. SEvEnsoN.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents- Washington, D. C.

